Volume question (1 Viewer)

[Hypem]

The region bounded by the curve y = sqrt(1-x^2) and the x-axis is rotated about the x-axis. Find the volume of the solid formed.

This is pretty straight forward, but they've simply found the area between 1 to 0 and not 1 to -1, so they found the area of a hemisphere. I thought you just find the volume of the entire sphere? Why'd they do this?

 

[Carrotsticks]

The region bounded by the curve y = sqrt(1-x^2) and the x-axis is rotated about the x-axis. Find the volume of the solid formed.

This is pretty straight forward, but they've simply found the area between 1 to 0 and not 1 to -1, so they found the area of a hemisphere. I thought you just find the volume of the entire sphere? Why'd they do this?

The volume of an entire sphere would be the correct answer.

If the question asked to rotate the curve around the Y axis, then a hemisphere would be correct.

If the question asked to rotate the curve around the X axis, for x > 0, then a hemisphere would be correct.

 

[HeroicPandas]

Who is 'they'?

and yeh i think u just find the volume of the entire sphere... using...



Unless the ________ is rotated around the y-axis, then u find the area of a hemisphere

 

[Hypem]

Thanks.

'They' is the people who wrote the answers to this practice test thing

 

[HeroicPandas]

Thanks.

'They' is the people who wrote the answers to this practice test thing

ignore me, i was being a dickhead (was a bad day)